Yankee Hill 4400 sRx QD Adapter 9mm Luger 3/8"-24 tpi 17-4 Stainless Steel

The Yankee Hill 4400 sRx QD Adapter is a quick-detach mounting interface built for suppressor users who want simplicity without compromise. Designed for 9mm Luger and smaller calibers, this adapter threads directly onto your barrel's 3/8"-24 TPI muzzle—the industry standard hub configuration—and pairs with YHM's sRx muzzle devices to create a low-profile, gas-tight suppressor system. If you're running a 9mm build and tired of fumbling with shims, timing concerns, or overly complex mounting solutions, this adapter eliminates those headaches while keeping your rig sleek and functional.

What sets the sRx adapter apart is its internal taper seal design. That large tapered surface sits ahead of the threaded portion and locks your suppressor firmly in place while simultaneously forming a solid gas seal. This means no pressure or debris creep onto the threads during firing—a real advantage for long-term durability and easy removal later. The whole system requires zero shiming and zero timing adjustments; mount it and go. At just 1.92 ounces and adding only 0.2 inches to your suppressor length, the 4400 keeps your overall package compact without adding unnecessary bulk or weight to your barrel.

Built from 17-4 stainless steel with a black oxide finish, this adapter is engineered to handle hard use. YHM backs every sRx component with a lifetime manufacturer's warranty, so you're investing in a mounting solution that's meant to outlast your current gun. Whether you're building a dedicated 9mm pistol suppressor host or adding a second QD adapter to your collection, the 4400 represents the straightforward, no-fuss engineering that suppressor users actually want.

Key Features

• Low-profile quick-detach mounting for 9mm Luger and smaller calibers
• Internal taper seal locks suppressor in place and contains gases—no thread buildup
• No shimming or timing required; true plug-and-play setup
• Minimal added length (0.2 inches) and weight (1.92 ounces)
• 17-4 stainless steel construction with black oxide finish for durability
• Compatible with YHM sRx muzzle devices and any suppressor with 1-3/8 threads
• Lifetime manufacturer's warranty

Specifications

Frequently Asked Questions

What suppressor muzzle devices does this adapter work with?

The 4400 sRx QD Adapter is designed to pair with YHM's sRx muzzle devices, specifically the 4405, 4405-MB, and 4401-MB models. It will also work with any suppressor featuring a 1-3/8 thread interface.

Does this adapter require shimming or timing?

No. The sRx QD Adapter is engineered with an internal taper seal that eliminates the need for shims or timing adjustments. Mount it and you're ready to shoot.

Can I permanently attach this adapter to my barrel?

Yes. While designed as a quick-detach mounting solution, the 4400 can also be permanently affixed to your barrel if you prefer a fixed suppressor setup.

What's included with the adapter?

The product includes the 4400 sRx QD Adapter itself. You will need to pair it with a compatible YHM sRx muzzle device and a suppressor with 1-3/8 threads to complete the mounting system.